An anaysis of the gene of Arabidopsis thaliana that is involved in the cell division, the cell differentiation, and the plastid division

我们鉴定了拟南芥核编码基因的一个新突变，称为皱褶叶（crl），影响所有植物器官的形态发生和质体的分裂。组织学分析表明，突变植株的茎尖分生组织、根尖和胚的细胞分裂平面发生畸变。此外，我们观察到在cr1突变体中，花序茎的皮层和内胚层细胞以及根内胚层细胞的分化模式受到了干扰。这些结果表明，在crl突变体中观察到的形态异常是由于异常的细胞分裂和分化。此外，crl突变体的细胞中含有的扩增质体数量减少，表明在crl中质体的分裂受到抑制。CRL基因编码一种新的蛋白，其分子质量为30 kDa，定位于质体包膜。CRL蛋白在包括蕨类植物和蓝藻在内的各种植物物种中都是保守的，但在其他生物中则不是。这些数据表明，CRL蛋白是质体分裂所必需的，在植物细胞分化和细胞分裂平面的调控中也起着重要的作用。

We identified a novel mutation of a nuclear-encoded gene, designated crumpled leaf (crl), of Arabidopsis thaliana that affects the morphogenesis of all plant organs and division of plastids. Histological analysis revealed that planes of cell division were distorted in shoot apical meristems, root tips, and embryos in plants that possess the crl mutation. Furthermore, we observed that differentiation patterns of cortex and endodermis cells in inflorescence stems, and root endodermis cells were disturbed in the cr1 mutant. These results suggest that morphological abnormalities observed in the crl mutant were due to aberrant cell division and differentiation. In addition, cells of the crl mutant contained a reduced number of enlarged plastids, indicating that the division of plastids was inhibited in the crl. The CRL gene encodes a novel protein with a molecular mass of 30 kDa that is localized in the plastid envelope. The CRL protein is conserved in various plant species including a fern, and in cyanobacteria, but not in other organisms. This data suggests that the CRL protein is required for plastid division, and also plays an important role in cell differentiation and the regulation of the cell division plane in plants.